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    <title>Document</title>
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<body>
    <script>
        let arr = [1, 2, 3, 4, 5, 6, 7]

        function fn(a) {
            let sum = 0
            let num = []
            for (let i = 0; i < a.length; i++) {

                if (a[i] % 2 !== 0) {
                    num.push(a[i])
                    sum += a[i]
                }
            }
            return sum / num.length ||  0
        }
        let res = fn(arr)
        console.log(res)
    </script>
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